The invention pertains to a safety seat for motor vehicles with the features of claim 1.
According to the state of the art, safety seats in armored motor vehicles are disconnected from the vehicle's floor, so that the forces which act when, for example, the vehicle travels over a mine are not transmitted directly by the structure of the seat to the vehicle occupant. Driving over a mine often has the result that not only the vehicle as a whole is lifted from the ground but also that the floor of the vehicle is buckled inward to a considerable extent. Seats attached to the vehicle floor thus transmit to the vehicle's occupants not only the impacts and vibrations encountered during normal driving but also the much greater forces of acceleration which occur when a mine explodes or the vehicle is involved in an accident.
It has already been proposed that safety seats be disconnected from the vehicle's structure by suspending the seats by the use of bracing straps. Bracing straps have the property of being unable to transmit compressive forces. The shockwave caused by a mine explosion is therefore not transmitted to the seat and thus not to the occupant. Seats which are held by bracing straps, however, require a larger number of fixation points than seats with rigid connections.
On the basis of U.S. 2005/0264082 A1, a seat for an armored land vehicle which is fastened to an upper suspension system for protection against mines and which comprises a seat cover and a restraint system belongs to the state of the art. The suspension system is formed by a suspension linkage, which is completely disconnected from the floor of the vehicle. A U-shaped seat frame is supported in articulated fashion on the suspension linkage and is connected to upper suspension points by the elastic suspension belts of the seat cover, wherein the elastic suspension belts comprise predetermined, energy-consuming break points. This light-weight arrangement is able to disconnect the seat from the vehicle's floor, but, in cases where the seat surface drops, it is possible for a situation to occur in which the belted-in person slides under the provided lap belt (submarining). This is a problem especially when the predetermined energy-consuming break points are torn apart not because of a mine explosion but because of a traffic accident of the vehicle, wherein, depending on the arrangement of the seat, the submarining effect can have very negative effects.
WO 02/26524 A1 discloses a safety seat with a damping mechanism, which is arranged in the area of the backrest. The seat structure comprises a seat unit and a back unit. The back unit comprises an upper part, which is connected to the structure of the motor vehicle, and a lower part, which can be dropped with respect to the upper part and which is connected to the seat unit. The energy-attenuating damper is arranged between the lower part and the stationary upper part and consists of a bending mechanism. When the lower part shifts with respect to the upper part of the back unit, a metal band is bent by the bending mechanism. As a result of the work of deformation, at least some of the energy which acts on the occupants when the vehicle drives over a mine, for example, is absorbed. The lower part of the seat drops as a whole. The loads on the occupants are reduced, but the energy-attenuating damper is comparatively complicated.